You have probably seen persistence of vision (POV) toys at some point– little LED dot-matrix displays that, when waved around, display a picture or a message that seems to hang in mid air. We’ve been playing with 16-segment LED displays lately, and it some point it occurred to us that we’d never seen an alphanumeric POV display. So, we went ahead and tried it out, and hey– it works! AlphaPOV is the result. It’s a neat effect since the clearly defined segments– designed for text– introduce a certain degree of legibility into the display.
The starting point for building this project is our LED Micro-Readerboard. Normally, the micro-readerboard shows one character at a time, so that you can read it sequentially while holding it still. Here, we use a (very slightly) modified version of the firmware that blinks the characters on and off at high speed. Read on for details, AVR source code and a few more pictures.